SSL - The condom that protects the pipe
SSL (Secure Socket Layer) - does it protect you or is it a condom open at both ends?
For
the last five or so years, SSL has been paraded as the technology that
secures the Internet. All you have to do is look and see the
padlock on the bottom of the screen and you can be sure it’s
safe. Is it true?
SSL
is a technology for providing a secure connection between two
places. It provides secure links, or pipes between wherever it
starts and wherever it stops.
What it does not do is actually
secure any of the data that passes through the pipe, or really know
where either end of the pipe actually is. What you can be sure of
is that anything put into one end of the pipe is going to come out
wherever the other end is.
But surely the data is fully
protected? Yes, whilst the data is in the pipe it is
protected. Now, assuming – and unfortunately that’s what we have
to do – that you know for sure where each end of the pipe is, and you
are sure that each end is very secure, and you know for certain who is
at each end, then you’re OK. If any of those is not true then you
do have a problem.
My data is SSL protected between the server,
and me so why should I worry? Well no one at the server end
really knows whom the data is from because they don’t know what your
identity is. They assume that data arriving through the pipe is
right, and that your identity can be presumed from the data, not the
other way around. Unfortunately there are hacker attacks that
divert your link through their own site, where they can pretend to each
end that they are the other entity without either end being the wiser.
(This is called a man-in-the-middle attack using web site spoofing.)
Once
your information gets to the server it stops being protected and anyone
can get to it, at least judging from the fact that hackers target web
sites first because that’s where they can guarantee to find large
quantities of names, addresses, credit card numbers and so on.
(Actually, SSL places such a heavy load on computers that they
now have other machines doing just the SSL encryption so your data is
potentially exposed even before it has a chance to get to the web
server, but that’s not the point.)
So there’s the problem. SSL
provides strong protection, but not actually to the data, just the
link. You might say it was a condom that protects the pipe.
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